Truck side frame



Mar. '27, 1923.

J. A. LAMONT TRUCK SIDE FRAME Filed 001? star JOHN A. LAMONT, OF CHICAGO, IlLLINOIS, ASSIGNOR TO AMERICAN STEEL FOUNDRIES,

an sic.

OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

TRUCK SIDE FRAME.

Application filed October 2, 1922. Serial No. 591,704.

To' all whom it may concern:

Be it known that 1, JOHN A. LAMONT, a citizen of.the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in a Truck Side Frame, of which the following is a specification.

This invention relates to a truck side frame.

One object of the invention is to provide a simple, durable and eflicient truck side frame which is uniformly strong and designed to overcome complex strains at points 1 which may be called critical points.

Another object is to provide an improved truck side frame adapted to meet the various requirements under severe service conditions.

These and other objects are accomplished to by means of the side frame illustrated on the accompanying sheet of drawings, in

which 7 Figure 1 is a side elevation of a side frame embodying my invention;

Figure 2 is a bottom plan view of the same side frame; and

Figure 3 is a fragmentary sectional View taken in the plane of line 3-3 of Figure 1.

The truck side frame illustrated is a cast m metal or integrally formed side frame having a compression member ll, a tension member 12 and bolster columns 13 extending therebetween. The various members of the side frame are of channel section with the exception of the tension member intermediate the bolster columns, which is box section. The upper wall 14; of the tension member intermediate the bolster column has laterally extending flanges 15 which serve W as bolster spring seats. Heretofore these laterally extending flanges 15, after extending longitudinally of the side frame to the inner walls of the bolster columns 13 have turned at a right angle and extended upwardly for the purpose of strengthening the side frame at such points. However, as a result of actual service conditions, it has been found that such side frames have developed cracks at the points where the inner sides of the bolster columnsjoin the tension member. A side frame at such points is subjected to severe tension strains. In ex- 7 planation of this it will be understood that the portion of the tension member inter-v mediate the bolster columns acts as a beam, as a result of the load imposed thereon through the bolster, and also acts as a part of the truss structure. Acting as a beam, it will be understood that although the upper portion of the tension member between the bolster columns and above the neutral axis is in compression, there is a high tension strain at the points 16 where the inner sides of the bolster columns join the tension member. Acting as the tension member in the truss structure, further tension strains are added to the metal at the points 16. The cumulative effect of'these tension strains is to impose serious composite tensional strains at such points. To overcome these excessive tensional strains at the described points 16 and to strengthen the side frame at such points to avoid such cracks, the flanges 15 have been extended from the points 16 diagonally upwardly instead of vertically upwardly with respect to the bolster column. In other words, the reinforcing flanges 17, which are extensions of the flanges 15, extend diagonally upwardly-substantially at an angle of 45 degrees, and are tangent to the arcs 18 at the critical points 16. Stated in another way, a line drawn perpendicular to the reinforcing flanges 17 attheir points of tangency 16 with respect to the arcs 18, will bisect the 90 degree angle between the tension member and the bolster columns inwardly of the latter.

As shown in Figure 2, the strengthening flanges 17 gradually taper off into the metal joint between the tension member and the bolster columns. As viewed in Figure 1, the reinforcing flanges 17 extend substantially along the lines of the tension forces in the tension member.

As a result of actual experiment,-it has been found that if the flanges 17 were extended beyond the columns 13 in the same horizontal plane with the flanges 15, the side frame would be weaker at the points 16 than they were with the flanges in their original vertical positions. It also has been ascertained by actual test readings that with the reinforcing flanges 17 extending in the direction shown in Figure 1, the side frame is increased in strength from thirty to forty percent at the critical points 16, these reinforcing flanges so positioned increasing the strength of the side frames at the points '16 a maximum amount.

It is my intention to cover all modifica-. tions of the, invention falling within the spirit and scope of-the following claims.

I claim e 1. A cast truck side frame including a tension member, a compression member, bolster columns extending therebetween, the lower inner sides of each of said columns joining said tension member in an arc, and

a reinforcing flange arranged tangent to each of said arcs at a point from which a line drawn perpendicularly to said tangent, will 'bisect the angle between the tension member and associated column.

-2. A cast trussed structure including a tension member, a compression member, a

strut extending therebetween, a lower side of said strut joining said tension member in an arc, and a reinforcing flange arranged tangent to said arc at a point from which a line drawn perpendicular to said tangent, will bisect the angle between the tension member and associated strut.

v 3. A cast truck side frame including a tension member, a, compression member, bolstercolumns extending therebetween, and

reinforcing ilanges extending diagonally u-pwardly from the points where the inner sides of said bolster columns join said tension member for counteracting high tensionbolster columns extending therebetween, the

top Wall of said tension member intermediate the bolster columns having laterally extending flanges to form a bolster spring seat, said flanges extending longitudinally of the side frame between said .bolster columns and then extending diagonally upwardly for counteracting high tension strains at the points Where the inner sides of the bolster columns join said tension memberl Signed at Chicago, Illinois, this 29th day of September, 1922.

JOHN LAMONT. 

